1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) and its driving method, and more particularly to an LCD that comprises a side radiation type light emitting diode (LED) and corresponding driving method.
2. Description of the Related Art
An LCD is a display apparatus including a liquid crystal material with an anisotropic dielectric constant injected between upper and lower transparent insulation substrates. Further, a common electrode, a color filter and a black matrix are formed on the upper substrate, and a switching element and a pixel electrode are formed on the lower substrate. In addition, a strength of an electric field formed in the liquid crystal material is controlled by applying a different potential to the pixel electrode and the common electrode to change an alignment of molecules of the liquid crystal material to thus control an amount of light transmitted through the transparent insulation substrates, thereby displaying desired images. In addition, a thin film transistor (TFT) LCD using TFTs as switching elements is commonly used.
Further, because the LCD is a light receiving type display apparatus that does not emit light by itself, a back light unit (BLU) for uniformly sustaining a brightness of an overall screen is installed at a rear surface of the LCD panel. A BLU includes a light emitting diode array and has either a top radiation type LED or a side radiation type LED.
In addition, the BLU using the side radiation type LED has an advantage in terms of panel uniformity and color mixing of the liquid crystal display panel. However, the side radiation type LED has a problem because the light is spread to cover a large area, and thus it is not suitable to be used for sectional driving (division driving) for which light irradiation is controlled at each unit area (UA) of the LCD panel.